Printing system having at least three printer devices as well as method for the operation of such a printing system

Abstract

A triplex printing system has three electrographic printer devices which enables both-sided, exactly registered printing of a paper web. For this purpose, the front side is printed in a first printer, the backside is printed in a second printer and the backside is printed again superimposed in a third printer. As a result of the arrangement of two printer chains having six printers, the structuring of a variable printing system adjustable dependent on function having a plurality of printer lanes is possible.

What is claimed is:  
     
       1. A printing system for registered printing of a web-shaped recording medium with a plurality of functionally coupled, electrographic printer devices, comprising: 
       a first printer device for printing a front side of the recording medium with a front side toner image of a first color and subsequently fixing in a first thermal fixing station;  
       a turnover station accepting the printed recording medium for turning the web-shaped recording medium over;  
       a second printer device accepting the turned over recording medium for printing a backside of the web-shaped recording medium with a backside toner image in the first or in a second color and subsequently fixing in a second thermal fixing station; and  
       a third printer device accepting the recording medium supplied from the second printer device for additionally printing the backside with an additional toner image in a color deviating from the color of the backside toner image, and subsequently fixing in a third thermal fixing station.  
     
     
       2. The printing system according to  claim 1  comprising a registration control unit for substantially exactly registered synchronization of the toner images printed by the printer devices at least between the backside toner image and the additional toner image. 
     
     
       3. The printing system according to  claim 1  whereby, for substantially exactly registered synchronization of the toner images to be printed, the printer device arranged upstream in a transport direction of the recording medium generates a synchronization mark whose position is sensed by a sensor unit of the printer device arranged downstream and is supplied as a position signal to a registration control unit that, dependent thereon, at least controls a recording medium drive of the printer device arranged downstream, whereby a loop buffer is formed between the upstream and downstream printer devices. 
     
     
       4. The printing system according to  claim 1  comprising a moistening unit arranged between a neighboring printing device that moistens the recording medium. 
     
     
       5. The printing system according to  claim 1  whereby at least one of the printer devices comprises a developer station that is rapidly changed dependent on a toner type being employed. 
     
     
       6. A method for operating a multi-functional printing system, comprising the steps of: 
       providing a first and a second printer chain of respectively three electrographic printer devices each designed for printing a web-shaped recording medium;  
       in a triplex mode, operating two printer chains as independent triplex printer chains that respectively print a separately supplied recording medium;  
       in a duplex mode, operating at least one of serially connected first printer devices, and second printer devices and third printer devices of the two printer chains as duplex printing systems for both-sided printing of a respective recording medium;  
       in a superimposition mode, operating in common the serially connected second printer devices and third printer devices of a printer chain for superimposed single-sided printing of a recording medium;  
       in a duplex superimposition mode for both-sided, superimposed printing of a single recording medium, operating in common the two serially connected, first printer devices, of each printer chain and the serially connected, second printer device and third printer device of the second printer chain; and  
       in a single print mode, operating at least one of the printer devices as a single printer.  
     
     
       7. The method of  claim 6  wherein at least one moistening unit moistens the recording medium. 
     
     
       8. The method according to  claim 6  whereby at least one of the printer devices comprises a developer station that is rapidly changed dependent on toner type. 
     
     
       9. A multi-functional printing system, comprising: 
       a first and a second printer chain each comprising a respective first electrographic printer device, a second electrographic printer device and a third electrophotographic printer device designed for printing a web-shaped recording medium;  
       the two first printer devices of the first and second printer chains are arranged following one another in a first transport direction and the second printer devices and third printer devices of the first and second printer chains are respectively arranged following one another in a second transport direction that crosses the first transport direction at approximately a right angle; and  
       at least one of a respective deflection station and turnover station is arranged in at least one of crossing regions of the transport directions and between the second and third printer devices in each of the first and second printer chains.  
     
     
       10. The printing system according to  claim 9  having at least one moistening unit that moistens the recording medium. 
     
     
       11. The printing system according to  claim 9  whereby at least one of the printer devices comprises a developer station that is rapidly changed dependent on toner type. 
     
     
       12. A method for registered printing of a web-shaped recording medium with a plurality of functionally coupled, electrographic printer devices in a triplex arrangement, comprising the steps of: 
       printing a front side of the recording medium with a front side toner image in a first color and subsequently fixing in a first thermal fixing station with a first printer device;  
       turning the printed recording medium over in a turnover station;  
       printing a backside of the web-shaped recording medium with a backside toner image in at least one of the first and a second color and subsequently fixing in a second thermal fixing station with a second printer device that accepts the turned over recording medium; and  
       additionally printing the backside with an additional toner image in a color deviating from the backside toner image and subsequently fixing in a third thermal fixing station with a third printer device.  
     
     
       13. The method according to  claim 12  whereby the recording medium is moistened following the first, second, and third thermal fixing stations. 
     
     
       14. The method according to  claim 12  whereby a photoconductor exhibits a slightly higher speed relative to the recording medium at least during transfer of the toner images from the photoconductor onto the recording medium. 
     
     
       15. A method for operating a multifunctional printing system with a control system that is driven function-dependent, comprising the steps of: 
       selecting at least one of the following operating function;  
       a triplex mode wherein two printer chains are operated as independent triplex printer chains that respectively print a separately supplied recording medium;  
       a duplex mode wherein at least one of serially connected first printer devices, and second printer devices and third printer devices of the two printer chains are operated in common as duplex printing systems for both-sided printing of a respective single recording medium;  
       a superimposition mode wherein serially connected second and third printer devices of a printer chain are operated in common for superimposed, single-sided printing of a recording medium;  
       a duplex superimposition mode for both-sided, superimposed printing of a single recording medium, whereby two serially connected, first printer devices of each printer chain and serially connected second and third printer devices of the second printer chain are operated in common; and  
       a single print mode wherein at least one of the printer devices is operated as a single printer.  
     
     
       16. The method according to  claim 15  whereby a photoconductor exhibits a slightly higher speed relative to the recoding medium at least during transfer of the toner images from the photoconductor onto the recording medium.